Another open-source communityhttp://wordpress.org is working on integrating their repository with Githubhttp://ma.tt/2014/10/sotw-2014/ for the very reasons you mentioned (Ctrl+F for the mention of github).
WordPress' tool, Trac, is SVN and therefore a bit of a bigger transition IMHO. The work is still ongoing.
There is a lively community that currently exists on Github. Encouraging folks to participate with tools that they are comfortable with is a win for wiki tech.
I would say that this is a smart move and agree with others that focusing on Phabricator as that’s the system with a longer life.
-Chris K. This electronic mail and any attached documents are intended solely for the named addressee(s) and contain confidential information. If you are not an addressee, or responsible for delivering this email to an addressee, you have received this email in error and are notified that reading, copying, or disclosing this email is prohibited. If you received this email in error, immediately reply to the sender and delete the message completely from your computer system.